Spectral domain optical coherence tomography as an effective screening test for hydroxychloroquine retinopathy (the “flying saucer” sign)

Abstract

PurposeWhile the long-term incidence of hydroxychloroquine (HCQ) retinopathy is low, there remains no definitive clinical screening test to recognize HCQ toxicity before ophthalmoscopic fundus changes or visual symptoms. Patients receiving HCQ were evaluated with spectral domain optical coherence tomography (SD OCT) to assess the feasibility of identifying HCQ retinopathy at an early stage.MethodsTwenty-five patients referred for the evaluation of hydroxychloroquine toxicity underwent a comprehensive ocular examination, Humphrey visual field (HVF) perimetry, time domain OCT, and SD OCT. Some patients with screening abnormalities also underwent further diagnostic testing at the discretion of the treating providers.ResultsFive patients were found to have SD OCT findings corresponding to HCQ toxicity and retinal damage as seen by clinical exam and/or HVF perimetry. Two patients with advanced toxicity were found to have significant outer retina disruption in the macula on SD OCT. Three patients with early HCQ toxicity and HVF 10-2 perifoveal defects were found to have loss of the perifoveal photoreceptor inner segment/outer segment (IS/OS) junction with intact outer retina directly under the fovea, creating the “flying saucer” sign. While two of these three patients had early ophthalmoscopic fundus changes, one had none.ConclusionOuter retinal abnormalities including perifoveal photoreceptor IS/OS junction disruption can be identified by SD OCT in early HCQ toxicity, sometimes even before ophthalmoscopic fundus changes are apparent. SD OCT may have a potential complementary role in screening for HCQ retinopathy due to its quick acquisition and because it is more objective than automated perimetry.

Microperimetric sensitivity in patients on hydroxychloroquine (Plaquenil) therapy

“…13 With advanced retinopathy, anatomical changes including perifoveal loss of the inner segment-outer segment junction of the photoreceptors, outer retinal thinning, and posterior displacement of the inner retina toward the RPE have been reported, which are indicative of a severe level of toxicity. 14,15 Similar patterns of Plaquenil toxicity have been described using ultra-high-resolution OCT. 16 These SD-OCT features, however, are seen largely in patients with paracentral scotomas or advanced maculopathy on HVF. None of our patients had these abnormalities.…”

A New Objective Parameter in Hydroxychloroquine-Induced Retinal Toxicity Screening Test: Macular Retinal Ganglion Cell-Inner Plexiform Layer Thickness

“…6,11,[20][21][22] Majority of the previous studies were related to the pathologies associated with the outer retinal segment involving retinal pigment epithelium and photoreceptors. 13,21,23 However, some other studies also demonstrated HCQassociated damage in the inner retinal segment. 11,19 In our study, we also found statistically significant thinning of RGC-IPL, which is a part of the inner retina; average RGC-IPL thickness, and all segments except inferior segment in the group of patients who were taking HCQ compared to the controls who were not taking the drug.…”

Use of microperimetry to evaluate hydroxychloroquine and chloroquine retinal toxicity

“…Evidence about the usefulness of FAF in early diagnosis is lacking. 18,19 Macular perimetry, funduscopic examination and photography continue to provide the highest yields of early cases. 17 It has been recently considered that revised guidelines, 4 emphasizing mfERG, SD-OCT or FAF, raised screening cost without improving case detection.…”